(a) Technical Field of the Invention
The present invention relates generally to a bulb socket, and in particular to a depression-to-release bulb socket, which allows mounting and dismounting of a bulb to be realized by a single depression of the bulb.
(b) Description of the Prior Art
A conventional lamp bulb comprises a bulb made of for example glass and having a lower end to which a base made of copper alloy and forming a threaded ring contact and a tip contact is mounted. A filament is arranged inside the bulb and is connected to two wires for supplying power to the filament. One of the wires extends out of the bulb and is attached to the ring contact of the base and the other wire is attached to the tip contact to respectively serve as negative and positive electrodes of the lamp bulb. A conventional bulb socket is constructed to receive the lamp bulb therein, comprising an insulation shell in which a conductive and threaded inner shell and a resilient conductive contact are arranged. The inner shell and the resilient contact of the socket are respectively connected to negative and positive terminals of a power source.
The bulb is received in socket in a threading manner by relative rotation therebetween in order to make the ring contact of the bulb engaging the inner shell of the socket and the tip contact of the bulb engaging the resilient contact of the socket. Thus, power can supplied from the external power source through the socket to the bulb. To remove the bulb from the socket, the bulb is rotated in a reversed direction to disengage the ring contact of the bulb from the inner shell of the socket.
The conventional threading type bulb and bulb socket, although effective in securing electrical engagement between the bulb and socket and allowing removal of the bulb from the socket, yet suffers the following disadvantages:
(1) The bulb must be rotated three or four full turns in order to securely fix in the socket and establish electrical engagement therebetween or to completely remove the bulb from the socket. This operation is time-consuming and inefficient.
(2) In rotating the bulb to detach the bulb from the socket, it is difficult to very precisely predict when the bulb is completely disengaged from the socket. Further, in doing the rotation, a user's hand, which cannot do a full turn, must repeatedly release and re-hold the bulb. With ignorance of the exact time when the bulb is disengaged from the socket, each time the user's release and re-hold the bulb in order to proceed with the next turn of rotation, it is always a serious concern of the user if the bulb will happen to disengage from the socket and falls when the user's hand just release the bulb. This is especially true is dismounting a large and heavy bulb and especially for a female user, who is usually weak with her hand's muscles. It is due to this reason that some female users still consider changing bulbs very difficult.
(3) If the glass bulb is broken, to remove the broken bulb from the bulb socket is an even more tough job, for the user cannot but to grip the broken glass or to grip a very tiny portion of the ring contact of the broken bulb that is exposed outside the socket and this often injure the user by being cut by the broken glass. Alternatively, a hand tool must be used to grip the base of the broken bulb in order to apply torque to the bulb. This is certainly troublesome and dangerous.
Thus, it is desired to have a bulb socket to allow an existing bulb having a threaded base to be secured and released in a more efficient and safer manner.